Nozzle head, cleaning system, method for cleaning and glass element

ABSTRACT

At least one glass element includes: a first end; a second end; and a hollow portion including a first end section including the first end of the at least one glass element, a middle section, and a second end section including the second end of the at least one glass element. Each section has an inner surface and an outer surface and all sections are of equal length. A ratio of a number of particles on the inner surface at the first end section and/or the second end section to a number of particles on the inner surface at the middle section is 20 or less.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority to European Patent Application No. EP20195761.0 filed on Sep. 11, 2020, which is incorporated in its entiretyherein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present invention relates to a nozzle head and to a cleaning systemcomprising such a nozzle head. The present invention also relates to amethod for cleaning a glass element, especially by a nozzle head or acleaning system provided according to the invention. The inventionfurther relates to a glass element and to a bundle.

2. Description of the Related Art

In the state of the art, glass elements such as glass tubes might besubject to contamination. Especially, particles might accumulate on thesurface, especially the inner surface, of the glass element.

The particles might originate, for example, from the manufacturingprocess of the respective glass element. In case of glass tubes, oneparticularly severe source of particles is the process of confectioningthe glass tubes from a glass tube strand. Here, the glass tubes might belengthened from the glass tube strand by sawing or otherwise cutting.This comes along with the creation of a considerable amount of particleswhich predominantly accumulate in the region of the end sections of theglass tubes. After confectioning, the glass tubes, especially their endsections, are subsequently heated again in order to seal and shape thecutting edge.

However, this might lead to the situation that the loose particles inthe end regions are connected with the surface of the glass tube in afirm manner. Of course, also particles originating from other sourcessuch as dust, educts or dirt from the environment might then be attachedto the glass element during heating likewise. Such particles oftencannot be removed in a subsequent washing procedure so that they arestill present in the final glass element.

Dependent on the purpose of the respective glass element, however,particles are highly undesired. For example, if the glass element isintended to be used as pharmaceutical container for holdingpharmaceutical compositions, a glass element of high quality, i.e.having no or almost no particles, is of particularly importance.Especially particles attached on the inner surface of the glass element,such as the surface of a glass tube facing towards the lumen, are ofhigh severity. If they get in contact with the pharmaceuticalcomposition, the pharmaceutical composition might be contaminated eitherin that substances from the particles leak into the pharmaceuticalcomposition or even that the particles as whole get off the surface ofthe glass element and into the composition.

In conventional manufacturing processes of, for example, glass tubes,thus, after lengthening and prior to heating, pressurized air is used toremove particles from the inner surface of the glass tubes. This isaccomplished in that a nozzle head injects an air stream into the glasstube from one end, in order to blow particles to the other end and,hence, out of the glass tube. While this procedure is easy to implementfrom a technical point of view, it suffers from disadvantages.

In this respect, only a portion of the air is actually injected into theglass tube, while the remainder is blown past the glass tube and mightraise dust and the like in the environment. This in turn might lead to anew source of contamination. Furthermore, particles are blown from oneend section to the other end section via the middle section,respectively, of the glass tube. Hence, there is the risk that thismiddle section afterwards is more contaminated as it initially has beenthe case. This is especially true since typically there are moreparticles in the end sections than in the middle section. It has alsobeen noted that the high pressure leads to high noise emissions. Inaddition, since a laminar air flow is built up within the glass tube,the flow velocity at the inner surface of the glass tube decreases overthe distance. Thus, the farther the particles are located away from theend section, the less the interaction forces between the injected airflow and the particles are. Glass tubes exceeding a specific length,therefore, might not be cleaned along their entire length in asufficient manner.

What is needed in the art is a way that allows a reduction of thecontamination with particles in an easy and cost-efficient manner forglass elements.

SUMMARY OF THE INVENTION

In some exemplary embodiments provided according to the invention, atleast one glass element includes: a first end; a second end; and ahollow portion including a first end section including the first end ofthe at least one glass element, a middle section, and a second endsection including the second end of the at least one glass element. Eachsection has an inner surface and an outer surface and all sections areof equal length. A ratio of a number of particles on the inner surfaceat the first end section and/or the second end section to a number ofparticles on the inner surface at the middle section is 20 or less.

In some exemplary embodiments provided according to the invention, acleaning system for cleaning the inside of a glass element with a fluidincludes a nozzle head. The nozzle head includes: a cleaning opening forreleasing a part of the fluid and pointing in a first direction; and apressure balancing opening for releasing a part of the fluid andpointing in a second direction. Two half spaces including a first oneand a second one are separated by a plane which is perpendicular to acenter axis of the nozzle head. A first direction vector of the firstdirection points in a direction at least one of towards the first halfspace or away from the second half space. A second direction vector ofthe second direction points in a direction at least one of towards thesecond half space or away from the first half space.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and advantages of this invention,and the manner of attaining them, will become more apparent and theinvention will be better understood by reference to the followingdescription of embodiments of the invention taken in conjunction withthe accompanying drawings, wherein:

FIG. 1 illustrates a cross-sectional view of a nozzle head providedaccording to the invention in a first configuration;

FIG. 2 illustrates a cross-sectional view of the nozzle head of FIG. 1in a second configuration;

FIG. 3 illustrates a perspective view of an exemplary embodiment of acleaning system provided according to the invention;

FIG. 4A illustrates a perspective view of another exemplary embodimentof a cleaning system provided according to the invention in an assembledstate;

FIG. 4B illustrates a perspective view of the cleaning system of FIG. 4Ain a disassembled state;

FIG. 5 illustrates a perspective view of another exemplary embodiment ofa cleaning system provided according to the invention;

FIG. 6 illustrates a perspective view of another exemplary embodiment ofa cleaning system provided according to the invention;

FIG. 7 shows an illustration demonstrating how a cleaning systemprovided according to the invention can be used for cleaning the insideof a glass element with a fluid; and

FIG. 8 shows an alternative to the illustration of FIG. 7.

Corresponding reference characters indicate corresponding partsthroughout the several views. The exemplifications set out hereinillustrate embodiments of the invention and such exemplifications arenot to be construed as limiting the scope of the invention in anymanner.

DETAILED DESCRIPTION OF THE INVENTION

Exemplary embodiments provided according to the invention include anozzle head for cleaning the inside of a glass element with a fluid, thenozzle head including: at least one cleaning opening for releasing atleast one part of the fluid and pointing in a first direction; and atleast one pressure balancing opening for releasing at least one part ofthe fluid and pointing in a second direction; two half spaces, a firstone and a second one, are separated by a plane which is perpendicular tothe center axis of the nozzle head, and the first direction vector ofthe first direction points in a direction towards the first half spaceand/or away from the second half space; the second direction vector ofthe second direction points in a direction towards the second half spaceand/or away from the first half space.

Exemplary embodiments provided according to the invention are, thus,based on the surprising finding that particles can be efficientlyremoved from a glass element if the nozzle head can be inserted into theglass element and remove particles by blowing them back to the closerend rather than via the middle section to the distant end, respectively,of the glass element. This is achieved by exemplary embodiments providedaccording to the invention in that the cleaning openings are pointing ina first direction so that fluid is also released in or towards a firsthalf space, i.e. in a direction backwards.

Furthermore, it has been realized that inserting the nozzle head intothe glass element allows for an interaction between the fluid and theparticles which is significantly increased. In addition, the particlesare not blown across the middle section of the glass element. Hence, amore efficient cleaning process is possible.

By providing pressure equalization in that a pressure balancing openingis provided, it can reliably be ensured that during blowing theparticles out of the glass element, other particles located past thenozzle head are not sucked into the fluid flow.

It is possible that the two halves of the glass element can be cleanedindependently from the two ends. Due to pressure equalization, noparticles are sucked from the other half. Likewise, in case a glasselement is cleaned from both ends by two respective nozzle heads inparallel, the pressure balancing opening prevents the creation of anegative pressure within the glass element and the suction of particles.

Since the nozzle head can be inserted into the glass element, the fluidflow is effective only within the glass element. Furthermore, the entirefluid flow released by the nozzle head, be it by the cleaning opening orthe pressure balancing opening, is directed outside the glass element.Thus, no particles from outside can get into the glass element. Due tothe fluid flow directed backward, it is also prevented that the fluidemitted by the pressure balancing opening lead to suction of air fromthe outside of the glass element.

The provided approach, thus, allows cleaning glass elements such asglass tubes of nearly arbitrarily length. Furthermore, it is sufficientand appropriate to insert the nozzle head only until the center of theglass element or even less, for example in the area where cleaning isrequired. Hence, the arm which holds the nozzle head can be designedshorter in length. This prevents oscillation of the arm, hence thenozzle head. Thus, possible damages of the glass element due tocollisions with the nozzle head are avoided.

It is acknowledged that according to the present invention, the term“opening,” especially with respect to a cleaning opening or a balancingpressure opening, may be understood as a three dimensional space whichmight be obtained e.g. by drilling.

It is acknowledged that according to the present invention the directionin which a cleaning opening or a pressure opening points may beunderstood as a direction which points outside the volume enclosed bythe outer shape of the nozzle head and which is normal to at least onecross section of the respective opening. Alternatively, the direction inwhich a cleaning opening or a pressure balancing opening points mightalso be understood as the direction into which the respective openingsubstantially releases the fluid.

The center axis of the nozzle head is, for example, the rotation axis ofthe nozzle head.

It has been found that when the nozzle head is used for cleaning glasselements, such as tubular elements, no negative pressure is created atthe ends of the respective glass element, especially at the ends of therespective tubular element. If a nozzle inside the glass tube were toblow perpendicularly against the wall, overpressure would result withonly one nozzle at both ends. Otherwise, if the cleaning nozzle weredirected towards one end of the glass element, the air stream generatedwould carry air from the other side and a negative pressure would becreated on the second side. Hence, particles from the environment wouldbe sucked into the glass element. For the provided nozzle head, thisentrainment of air is suppressed. A small opening, such as a slit, inthe nozzle, directed towards the second end of the pipe, may besufficient for this. Therefore, the provided nozzle head allows removingparticles from inside the glass element, such as a tubular element,without causing further contaminations.

In some embodiments, it might be provided that the nozzle head furthercomprises at least one feeding opening for feeding the nozzle head withthe fluid and pointing in a third direction. In some embodiments, (i)the third direction vector of the third direction points in a directiontowards the first half space and/or away from the second half space,(ii) the third direction vector is anti-parallel to the second directionand/or (iii) the third direction vector is parallel to the center axisof the nozzle head.

A feeding opening allows easy and secure attachment of a fluid supplyline to the nozzle head.

A respective orientation of the feeding opening allows obtaining anozzle head which can be handled in a safe manner due to properdistribution of the different openings across the nozzle head.

It is acknowledged that according to the present invention, the term“opening” with respect to a feeding opening may be understood as a threedimensional space which might be obtained e.g. by drilling.

It is acknowledged that according to the present invention, thedirection in which a feeding opening points may be understood as adirection which points outside the volume enclosed by the outer shape ofthe nozzle head and which is normal to at least one cross section of thefeeding opening.

In some embodiments, it might be provided that the nozzle head isconfigured so that a first ratio of the amount of fluid released by thepressure balancing opening to the amount of fluid released by thecleaning opening (mass/mass) is 0.2 or more, such as 0.5 or more, 0.9 ormore, 1 or more, or 1.5 or more, and/or is 20 or less, such as 10 orless, 5 or less, 1 or less, 0.9 or less, or 0.5 or less, especially whenthe nozzle head is fed with a fluid through the feeding opening with 1to 10 bar absolute, such as 2 to 6 bar absolute, or 3 bar absolute;and/or that the second direction vector is parallel to the center axis,the first direction vector is neither parallel nor anti-parallel to thecenter axis and/or an angle between a line defined by the firstdirection vector and a plane perpendicular to the center axis is between10 degrees and 89 degrees, such as between 20 degrees and 80 degrees,between 30 degrees and 80 degrees, or between 40 and 80 degrees.

An appropriate first ratio allows obtaining pressure conditions whichlead to a particularly good cleaning result. It turned out that at bothends of a glass element, such as a tubular element, a negative pressurecan particularly be avoided for the proposed values of the first ratio.The ratio may take values larger than one or smaller than one.

In some embodiments, the nozzle head is configured such that in bothhalf spaces within the tubular element an overpressure with respect tothe environment outside the tubular element is present.

An exemplary first ratio allows obtaining a particularly efficientoperational mode of the nozzle head and a good cleaning result.

In some embodiments, the first ratio is 1 or more, such as 1 to 5, 1 to2, 1.0 to 1.5, or 1.00 to 1.3. If the ratio is 1 or more, such as morethan 1.00, the cleaning of both end sections of a glass element can beimproved.

This configuration is particularly useful, for example, if a tubularelement is subject to a cleaning process. Then, in case that the part ofboth half spaces within the tubular element have a pressure with respectto the environment of the tubular element, a cleaning process can beconducted in an easy and efficient manner. Furthermore, a first ratio of1 or more may prevent the creation of a negative pressure within theglass element and the suction of particles.

In some embodiments, the first ratio is less than 1. For example, thefirst ratio may be between 0.1 and 0.99, between 0.2 and 0.9, or between0.2 and 0.8.

If the orientations of the cleaning and pressure balancing opening arechosen appropriately, the fluid flow can effectively interact with theparticles. For example, it has been proven to be beneficial that thepressure balancing opening emits the fluid flow parallel to the centeraxis and the cleaning opening emit the fluid flow in a directionenclosing some angle with the center axis in the opposite direction.

In some embodiments, for each cleaning opening, the angles between therespective line defined by the respective first direction vector and theplane perpendicular to the center axis fulfill the stated condition.

In some embodiments, it might be provided that the nozzle head comprisesa plurality of cleaning openings, such as between 2 and 50 cleaningopenings, between 2 and 30 cleaning openings, between 2 and 12 cleaningopenings, or 2, 4, 6, 8, 10 or 12 cleaning openings, each cleaningopening pointing in a first direction having a respective firstdirection vector.

The plurality of cleaning openings allows to distribute the fluidequally around the nozzle head. Thus, a more precise and efficientcleaning of glass elements is possible.

In some embodiments, at least some of the cleaning openings are arrangedalong at least one section of at least one circle extending around theouter circumference of the nozzle head, especially the circle isconcentrically with the center axis of the nozzle head.

The nozzle head may comprise 6 cleaning openings.

It is acknowledged that every cleaning opening might point in adifferent first direction and typically will do so. Hence, there mightbe several first directions and the number of first directions equalsthe number of cleaning openings. However, in case that two or more of aplurality of cleaning openings point in a common first direction, thenumber of different first directions can also be less than the number ofcleaning openings.

In some embodiments, it might be provided that the nozzle head comprisesone single feeding opening and/or comprises a plurality of feedingopenings, such as 2 to 10, 2 to 3, most or 2 feeding openings; that thenozzle head comprises one single pressure balancing opening and/orcomprises a plurality of pressure balancing openings, such as 2 to 10, 2to 3, or 2 pressure balancing openings; and/or that the nozzle headcomprises one single feeding opening and one single pressure balancingopening and the only one feeding opening is arranged opposite to theonly one pressure balancing opening along the center axis.

A single pressure balancing opening allows providing a nozzle head whichis robust and easy to use.

A single feeding opening allows providing a nozzle head which is robustand easy to use.

If the nozzle head comprises one single pressure balancing opening andone single feeding opening, an efficient nozzle head can be provided. Ifthe openings are arranged opposite along the center axis, the nozzlehead has improved symmetry which reduces instabilities and possibleoscillations during use.

In some embodiments, it might be provided that at least some or all ofthe one or more cleaning openings is/are arranged within the plane, suchas perpendicular to a line defined by the third direction vector, and/orarranged such that they are crossed by the plane, such as perpendicularto a line defined by the third direction vector.

A particularly symmetric design of the nozzle is obtained if all or atleast some of the cleaning openings determine at least in part theposition and/or orientation of the plane. This in turn allows that thenozzle head produces a fluid output of high symmetry, hence, having highcleaning capabilities.

In some embodiments, it might be provided that at least one of thecleaning openings, such as all of them, is/are slit-shaped, such as 360degrees slit-shaped, or round-shaped.

A round-shaped cleaning opening is easy to fabricate and produces anexemplary fluid stream. A slit-shaped cleaning opening is suitable toobtain a uniform fluid stream over a particularly larger or bendedoutput section.

In some embodiments, it might be provided that at least one of thepressure balancing openings, at least one of the cleaning openingsand/or at least one of the feeding openings, such as all of therespective openings, is/are arranged concentrically with regard to thecenter axis.

For example, the cleaning opening might be a 360-degrees slit openingwhich can be particularly easily provided in that it is arrangedconcentrically with regard to the center axis.

If the feeding opening(s) and/or the pressure balancing opening(s) areconcentrically arranged, the handling of the nozzle head is more secureand convenient.

In some embodiments, it might be provided that a second ratio of thearea of the cross section(s) of the pressure balancing opening(s) to thearea of the cross section(s) of the cleaning opening(s) (mm²/mm²) is 0.2or more, such as 0.5 or more, 0.9 or more, 1.0 or more, or 1.50 or more;and/or that the second ratio is 20 or less, such as 10 or less, 5 orless, 1 or less, 0.9 or less, or 0.5 or less.

An exemplary second ratio allows obtaining a particularly efficientoperational mode of the nozzle head and a good cleaning result.

In some embodiments, it might be provided that the nozzle head comprisescarbon fibers, a metal, a metal alloy or a polymer; for example, thenozzle head may comprise aluminum, steel, brass, polytetrafluorethyleneor polyoxymethylene.

If a plastic material is chosen for the nozzle head, a quite robustnozzle head might be obtained. In addition, the risk that the nozzlehead damages the glass element during operation can be further reducedin that.

For example, the nozzle head can be fabricated using injection molding.

In some embodiments, it might be provided that the maximum outerdiameter of the nozzle head is 50 mm or less, such as between 1 mm and50 mm, between 2 mm and 25 mm, or between 3 mm and 18 mm.

An exemplary outer diameter allows better cleaning of glass elements.

In some embodiments, it might be provided that the nozzle head comprisesat least one supply channel or supply channel network for supplying thefluid from the feeding opening to the pressure balancing opening(s)and/or the cleaning opening(s), wherein the supply channel may comprisea cylindrical portion, such as a cylindrical portion having a diameterof 1.5 mm or more and/or of 25.0 mm or less.

A supply channel allows proper and efficient distribution of the fluidwithin the nozzle head. A supply channel of appropriate diameter allowsmatching operational requirements such as maximum allowable pressureapplied to the nozzle head. Thus, safety is increased.

In some embodiments, it might be provided that all pressure balancingopening(s) and cleaning opening(s) are in fluidal communication witheach other via the supply channel or the supply channel network.

The nozzle head can be particularly easily and cheaply manufactured ifthe respective openings are in fluidal communication with each other viathe supply channel. Essentially, it is possible that the openings arejust drilled into the nozzle head until they are connected with thesupply channel or supply channel network which might have previouslybeen provided within the nozzle head.

In some embodiments, it might be provided that the nozzle head furthercomprises at least one adjustment element for adjusting a third ratio,wherein the third ratio is the ratio of the amount of fluid released byone or more, such as all, of the cleaning openings, to the amount offluid released by one or more, such as all, of the pressure balancingopenings (mass/mass). In some embodiments: (i) the third ratio isadjusted by the adjustment element in that at least one cross section ofeach of the cleaning opening(s) and/or of the pressure balancingopening(s) is adjusted, especially increased or decreased; (ii) theadjustment element comprises at least one dosage ring and/or at leastone part, especially an end section, of a fluid supply line; (iii) theadjustment element is arranged at least in part within the nozzle head;(iv) the adjustment element is moveable within the nozzle head,especially along an adjustment direction parallel to the center axis;(v) the third ratio is or can be adjusted by moving the adjustmentelement, especially along the adjustment direction; (vi) the third ratiois measured for a fluid pressure of 1 to 10 bar absolute, such as 2 to 6bar absolute or 3 bar absolute; and/or (vii) the nozzle head furthercomprises a fixing element, such as a locking nut, for fixing theadjustment element at a particular position, especially for preventing amovement along the adjustment direction.

The adjustment element allows utilizing the nozzle head under differentconditions. Dependent on the particular scenario, different fluidvolumes can be easily chosen. Providing the adjustment element is alsopossible in an easy manner.

If the adjustment element comprises a dosage ring, the third ratio canbe chosen very precisely. If the adjustment element comprises a part ofthe fluid supply line, a very compact setup is obtained.

If the adjustment element is arranged within the nozzle head, a compactsetup is obtained. Furthermore, the adjustment element is securelyprovided.

Adjusting the third ratio is possible in a particularly easy and precisemanner if the adjustment element is moveable.

A fixing element can be provided in an easy manner while the entirenozzle head still remains of compact design.

In some embodiments, it might be provided that the nozzle head comprisesa first threaded portion, the first threaded portion may be at least inpart comprised by at least one section of the feeding opening, and theadjustment element may comprise a second threaded portion, which maycooperate with the first threaded portion of the feeding opening,especially the cooperation allows moving the adjustment element alongthe adjustment direction.

A threaded portion allows securely attaching other elements to thenozzle head. If the threaded portion is provided at the feeding opening,respective feeding lines can be arranged in a safe manner.

If the adjustment element has a threaded portion, it is possible thatthe movement of the adjustment element within the nozzle head ismediated by the cooperation of the threaded portions. If the firstthreaded portion is comprised by at least one section of the feedingopening, the adjustment element might be moveable at least in partwithin the feeding opening.

In some embodiments, it might be provided that the nozzle head isconfigured so that the cleaning opening(s) and/or the pressure balancingopening(s) rotate around the center axis when fluid is released by thecleaning opening(s) and/or the pressure balancing opening(s), whereinthe rotation is driven by the fluid jet released by the cleaningopening(s) and/or the pressure balancing opening(s).

The cleaning results obtained with the nozzle head are of particularlyhigh quality if the nozzle head rotates.

In some embodiments, it might be provided that the cleaning opening(s)and/or the pressure balancing opening(s) are configured such that aline, such as all lines, defined by the first and/or second directionvector(s) do(es) not cross a line defined by the third direction vector;and/or that the cleaning opening(s) and/or the pressure balancingopening(s) are configured such that the fluid is helically released bythe respective opening(s).

In some embodiments, it might be provided that the nozzle head isconfigured such that, when it is inserted into a glass element,especially a tubular glass element, e.g. a tubular glass element havingan inner diameter of 0.5 cm to 10 cm, such as of 2 cm, a cylindricalportion of 2 cm to 200 cm and/or a length of 10 cm to 200 cm, such as of100 cm, comprising a first end section and a second end section, in thefirst and the second end sections an excess pressure with regard to theambient pressure exists, when at least one part of the fluid is releasedby the cleaning opening and at least one part of the fluid is releasedby the pressure balancing.

In some exemplary embodiments provided according to the invention, acleaning system for cleaning the inside of a glass element with a fluidincludes: a nozzle head as described herein; and a fluid supply line,which is connected to the feeding opening of the nozzle head.

It is the astonishing finding that the nozzle head can be used incombination with a fluid supply line connected to the nozzle head, sothat a respective cleaning system takes all advantages described abovewith respect to the nozzle head as well.

In some embodiments, it might be provided that (i) the nozzle head isarranged at one end of the fluid supply line; (ii) the nozzle head isdesigned integrally with the fluid supply line; (iii) the adjustmentelement is provided by the fluid supply line; (iv) the adjustmentelement is designed integrally with the fluid supply line; (v) thesupply line has a tubular shape, for example comprises a tube; and/or(vi) the fluid supply line or the nozzle head and the fluid supply linehas a length of 5 cm to 100 cm, such as 10 cm to 75 cm or 20 cm to 50cm.

An integral design of the nozzle head and the fluid supply line providesa particularly robust cleaning system and a reduced number of pieces.

An integral design of the adjustment element and the fluid supply lineprovides a particularly robust cleaning system and a reduced number ofpieces.

A tubular shape may be provided for glass elements of hollow cylindricalshape.

In some embodiments, it might be provided that (i) the cleaning systemis configured such that the nozzle head and/or the fluid supply line canbe moved back and forth, especially along the center axis of the nozzlehead and/or parallel or anti-parallel to the second and/or thirddirection; (ii) the cleaning system is configured such that the nozzlehead, and in some embodiments also at least a part of the fluid supplyline, is inside the glass element when the fluid is released by thenozzle head; (iii) the cleaning system is configured to clean the glasselement from particles by releasing a fluid by the nozzle head while thenozzle head is located inside the glass element; and/or (iv) thecleaning system is configured to clean the glass element from particlesin that the nozzle head and/or the fluid supply line is moved along adirection parallel to the second and/or third direction, such as insidethe glass element, while the nozzle head does not release fluid and thenozzle head and/or the fluid supply line is moved along a directionparallel to the second and/or third direction, such as out of the glasselement, while the nozzle head releases fluid.

The movement of the nozzle head and/or the fluid supply line allows thatthe nozzle head can be moved into the glass element, such as a glasstube, in an easy and efficient manner.

If the nozzle head and possibly also the fluid supply line is inside theglass element when the fluid is released by the nozzle head, it can beensured that particles which are attached at an end section are notblown further into the glass element. Instead they are blown out of theglass element via the near end section.

Hence, if the fluid is released by the nozzle head while the nozzle headis located inside the glass element, the particles can be purposefullyblown directly towards the closer end of the glass element. In addition,the direct interaction between the fluid released by the cleaningopening and the particles is increased. All this improves the quality ofthe cleaning process.

If the nozzle head is moved into the glass element prior to releasingfluid from the nozzle head and is moved back outside the glass elementwhile releasing fluid from the nozzle head, the particles areefficiently removed from the glass element because they are moved so tosay from inside to outside.

Since the cleaning opening(s) are close to the inner surface of theglass element, much higher and constant flow velocities are obtainedcompared to a laminar flow. It is also noted that the amount of fluidcan be reduced significantly with the approach disclosed herein due todirection interaction of the fluid with the particles. This also reducesnoise emissions.

In some embodiments, it might be provided that (i) the cleaning systemfurther comprises at least one fixation unit, such as a conveyor belt ora roll, for holding the glass element during cleaning in a fixedposition; (ii) the cleaning system further comprises at least one fluidsupply element, such as a tank, a recycling facility or a fluid filtersystem, for supplying fluid to the nozzle head via the fluid supplyline, the fluid supply element supplying a fluid, such as a gas,especially a noble gas, such as helium (He), neon (Ne) or argon (Ar),nitrogen, oxygen, carbon dioxide or air, a liquid, water vapor, or amixture thereof; and/or (iii) the water content in the fluid supplied tothe nozzle head is 10 mass-% or less; such as 1 mass-% or less, 0.1mass-% or less, or 0.01 mass-% or less.

A fixation unit allows providing a secure cleaning process. For example,rolls can be used which apply pressure on the glass element, e.g. fromabove. This prevents that the glass element, such as a pipe, is blownaway during the cleaning process.

A fluid supply element allows ensuring a reliable supply of fluid to thecleaning system.

A reduced water content allows performing the cleaning process moreefficiently.

In some embodiments, it might be provided that the cleaning system isconfigured to rotated either the glass element and/or the nozzle headwhile the fluid is released by the nozzle head.

The relative rotation allows performing a particularly efficientcleaning process. This is because the area of direct interaction betweenthe fluid and the surface of the glass element is increased.

In some embodiments, it might be provided that the cleaning systemcomprises a vibrator unit configured to shake the glass element at leastfrom time to time during the cleaning process, especially with afrequency of 100 to 10000 Hz, such as 200 to 5000 Hz or 250 to 4000 Hzand/or an amplitude of 0.1 mm to 10 mm, such as 0.5 mm to 1 mm or 0.7 mmto 0.9 mm.

The vibration unit allows performing a particularly efficient cleaningprocess in that the glass element is shaken. This allows supportingmovement of particles in combination with the fluid.

For example, shaking may mean that pulse-like vibrations are applied.This provides an effective way of cleaning.

In some embodiments, it might be provided that (i) the cleaning systemis configured to release at least one fluid stream through one of thecleaning and pressure balancing openings, such as all fluid streamsthrough all cleaning and pressure balancing openings, with a flow-rateof between 5 and 100 m³ per hour; (ii) the ratio of the maximum outerdiameter of the nozzle head to the inner diameter of the glass elementis between 0.5 and 0.9; (iii) the ratio of the outer diameter of thefluid supply line, especially of the threaded portion, to the innerdiameter of the glass element is between 0.2 and 0.9; and/or (iv) thecleaning system is configured to release the fluid in a continuousmanner and/or in a pulsed manner through one or more, such as all,cleaning and pressure balancing openings.

An exemplary flow-rate allows providing an efficient cleaning process.

If the difference between the outer diameter of the nozzle head and theinner diameter of the glass element is chosen appropriately, the fluidcan interact with the particles attached to the glass element, such as aglass tube, in an exemplary manner.

A fluid provision in a pulsed manner improves interaction between thefluid flow and the glass element. A fluid provision in a continuousmanner allows an easy implementation of the cleaning system.

In some embodiments, it might be provided that the cleaning systemcomprises a glass element, especially a tubular glass element, e.g. atubular glass element having an inner diameter of 0.5 cm to 10 cm, suchas of 2 cm, a cylindrical portion of 2 cm to 200 cm, and/or a length of10 cm to 200 cm, such as of 100 cm, comprising a first end section and asecond end section, the nozzle head being configured that in the firstand the second end sections an excess pressure with regard to theambient pressure exists, when at least one part of the fluid is releasedby the cleaning opening and at least one part of the fluid is releasedby pressure balancing opening.

In some exemplary embodiments provided according to the invention, amethod for cleaning a glass element, which may use the previouslydescribed nozzle head provided according to the invention or anyembodiment described herein or by the previously described cleaningsystem provided according to the invention or any embodiment describedherein, the method comprising the steps of:

-   -   providing a glass element;    -   inserting a nozzle head inside the glass element along a        specific direction, which may be parallel to the second and/or        third direction, while the nozzle head does not release fluid;        and    -   releasing fluid out of the nozzle head, such as while moving the        nozzle head, especially within the glass element, along a        direction which is opposite to the specific direction.

Exemplary embodiments provided according to the invention are, thus,based on the finding that particles are efficiently removed from theglass element if they are blown from inside to outside. This can berealized in an efficient manner in that the nozzle head is insertedinside the glass element while the nozzle head does not release fluidand the nozzle head is moved inside the glass element while releasingfluid from the nozzle head.

In some embodiments, it might be provided that fluid is released out ofthe nozzle head, while moving the nozzle head within the glass elementin the third direction until the nozzle head has left the glass element.

In some embodiments, it might be provided that the steps of insertingand releasing are performed in 1 minute or less, such as 30 seconds orless, 15 seconds or less, 10 seconds or less, or 5 seconds or less.

In some exemplary embodiments provided according to the invention, aglass element includes a first end, a second end and a hollow portion,the hollow portion including: i) a first end section comprising thefirst end of the glass element, ii) a middle section, and iii) a secondend section comprising the second end of the glass element, each sectionhaving an inner and an outer surface and all sections are of equallength, the ratio of the number of particles on the inner surface at thefirst and/or the second end section to the number of particles on theinner surface at the middle section is 20 or less.

Exemplary embodiments provided according to the invention are, thus,based on the surprising finding that a glass element is particularlysuited for holding sensitive substances such as pharmaceuticalcompositions if the surface enlargement of the glass element is limited.It turned out that a low surface enlargement prevents or at leastreduces the diffusion of substances contained in the glass material to acomposition hold by the glass element.

It has been astonishing that controlling the ratio of the number ofparticles allows producing a high quality glass element which isparticularly suitable for holding pharmaceutical compositions. Theapproach disclosed herein makes it quite easy to produce a respectiveglass element of high quality.

Determining the relevant particles may be conducted according to thefollowing method:

In a dark room, the glass element to be examined is illuminated, e.g.with 5000 lux. The particles are identified by the diffraction,reflection or absorption of the light. A hand microscope, for example ahand microscope “Wide Stand Microscope” from PEAK, can be used toidentify the particles. The particles optically identified in this wayare visibly marked. The glass element marked in this way is viewed alongthe normal to the surface under a light microscope, for example the AxioImager M2m from Zeiss, with lens LD EC Epiplan 50×/0.55 HD DIC andocular PI 10×/2, to characterize and measure the length of theparticles. Herein, the size of the particles relates to the largestextension visible in the viewing plane (Feret diameter). With this typeof measurement, it is consciously accepted that the maximum longitudinalextent of a three-dimensional particle can also extent in the directionof the optical axis of the microscope, i.e. along the normal. In thiscase, a smaller value for the size of the particle is obtained than theactual value of the maximum longitudinal extent of the three-dimensionalparticle, for example the glass particle. It is acknowledged that withthis method, at least particles having a size of 50 μm or more, i.e. thelargest extension visible in the viewing plane, can be characterizedwith regard to their size and kind, e.g. glass, metal, dust or salt.Optional, particles having a size of less than 50 μm may not beconsidered as particles according to the invention described herein inlight of this method.

If not stated otherwise, in the context of the present application, aglass element may comprise a first end, a second end and/or a hollowportion, such as a cylindrical hollow portion, wherein the hollowportion may comprise a first end section comprising the first end of theglass element, a middle section, and/or a second end section comprisingthe second end of the glass element. Each section may have an innerand/or an outer surface. Each of all sections may be of equal length.

In some embodiments, it might be provided that the ratio of the numberof particles on the inner surface at the first and/or the second endsection to the number of particles on the inner surface at the middlesection is 15 or less, such as 10 or less, 8 or less, 6 or less, 4 orless, 2 or less, and/or 1.0 or more.

A glass element of particularly high quality can be obtained forrespective ratios.

In some embodiments, it might be provided that the number of particleson the inner surface at the first and/or the second end section is 0 ormore, such as 50 or more, 100 or more, and/or 1000 or less, such as 900or less, 800 or less, 700 or less, 600 or less, 500 or less, 400 orless, 300 or less, or 200 or less.

It has been found that the quality and safety of the glass element isimproved if the number of particles is restricted. This allows obtaininga smooth surface.

In some embodiments, it might be provided that the number of particleson the inner surface at the middle section is 0 or more, such as 50 ormore, 100 or more, and/or 1000 or less, such as 900 or less, 800 orless, 700 or less, 600 or less, 500 or less, 400 or less, 300 or less,or 200 or less.

It has been found that the quality and safety of the glass element isimproved if the number of particles is restricted. This allows obtaininga smooth surface.

In some embodiments, it might be provided that the number of particleson the inner surface at the first and/or the second end section per cm2is in average 10 or less, such as 9 or less, 8 or less, 7 or less, 6 orless, 5 or less, 4 or less, 3 or less, 2 or less, or 1 or less, and/orthe number of particles on the outer surface at the first and/or thesecond end section per mm2 is 10 or less, such as 9 or less, 8 or less,7 or less, 6 or less, 5 or less, 4 or less, 3 or less, 2 or less, or 1or less.

It has been found that the quality and safety of the glass element isimproved if the density of particles is restricted. This allowsobtaining a smooth surface.

In some embodiments, it might be provided that (i) the particle size,such as its largest extension, is 50 μm or more, such as 60 μm or more,70 μm or more, 80 μm or more, 90 μm or more, 100 μm or more, 110 μm ormore, 120 μm or more, 130 μm or more, 140 μm or more, or 150 μm or more;and/or (ii) the particle size, such as its largest extension, is 1000 μmor less, such as 900 μm or less, 800 μm or less, 700 μm or less, 600 μmor less, 500 μm or less, 400 μm or less, 300 μm or less, 200 μm or less,or 150 μm or less.

It is the astonishing finding that only particles of respectiveextension are relevant for assessing the quality of the glass element.It is, therefore, sufficient to address particularly these particleswhile others may remain unaffected. This reduces costs for providinghigh quality glass elements.

It may be understood by the person skilled in the art that particleshaving a size outside of the stated range can nevertheless be present onthe inner and/or outer surface, however, these particles are not takeninto consideration for the ratio. For example, if the particle size were50 μm or more, then there can be no or very many particles present onthe inner and/or outer surface having a size of 2 μm, but they would notbe relevant for the ratio.

In some embodiments, it might be provided that the glass element doesnot contain any particles on the inner surface at the first and/or thesecond end section having a particle size, such as having a largestextension, of 1000 μm or more, such as 900 μm or more, 800 μm or more,700 μm or more, 600 μm or more, 500 μm or more, 400 μm or more, 300 μmor more, 200 μm or more, 150 μm or more, 100 μm or more, or 50 μm ormore.

If particles are restricted in their size, it is easily possible toprovide high quality glass elements.

In some embodiments, it might be provided that the ratio of the numberof particles on the inner surface of the first end section, the middlesection, the second end section and/or any combination thereof, to thenumber of particles on the outer surface of the respective section(s),is between 0.5 and 1.5, such as between 0.9 and 1.1.

It turned out that a particularly improved glass element is obtained ifinner and outer surface are similar with respect to their roughness.This finding has its basis in the fact that a similar roughnesssurprisingly improves strength of the glass element.

In some embodiments, it might be provided that the particles areinorganic particles and/or are selected from glass, metal, dust, salt.

It may be understood by the person skilled in the art that particles ofother materials than these stated can nevertheless be present on theinner and/or outer surface, however, these particles are not taken intoconsideration for the ratio. For example, if the particles were glass,then there can be no or very many salt particles present on the innerand/or outer surface, but they would not be relevant for the ratio.

In some embodiments, it might be provided that the length of the hollowportion is 2 cm or more, such as 10 cm or more, 20 cm or more, 30 cm ormore, 40 cm or more, 50 cm or more, 110 cm or more, and/or 500 cm orless, such as 400 cm or less, 300 cm or less, 200 cm or less, 100 cm orless, or 50 cm or less.

A glass element of respective length allows to easily produce a surfacewith improved quality.

In some embodiments, it might be provided that the outer diameter of thehollow portion is 3 mm or more, such as 4 mm or more, 5 mm or more, 6 mmor more, 7 mm or more, 8 mm or more, 9 mm or more, 10 mm or more, 15 mmor more, 20 mm or more, and/or 20 cm or less, such as 15 cm or less, 10cm or less, 5 cm or less, 4 cm or less, 3 cm or less, or 2 cm or less.

A glass element having a respective diameter may be manufactured in aneasy manner.

In some embodiments, it might be provided that (i) the hollow portion isat least in part designed as hollow cylindrical portion; (ii) the glasselement is a glass tube; and/or (iii) the glass element comprises, suchas is made of, a borosilicate glass, a soda lime glass oraluminosilicate glass.

If the glass element is of a respective glass material, it can be usedin a plurality of scenarios.

A glass tube of high quality is of particular interest.

In some embodiments, it might be provided that the first end of theglass element is an open end, especially the lumen of the glass elementbeing in fluidal communication with the environment of the glass elementvia the first end of the glass element, and/or the second end of theglass element is an open end, especially the lumen of the glass elementbeing in fluidal communication with the environment of the glass elementvia the second end of the glass element.

A glass element having one or more open ends allows to access the lumeneasily.

In some embodiments, it might be provided that the first end of theglass element is a closed end and/or the second end of the glass elementis a closed end.

A glass element having one or more closed end allows reducing or evenpreventing further contaminations.

In some embodiments, it might be provided that the glass element is orcan be produced by a Danner process and/or a Vello process. This allowsfor a cheap and efficient manufacturing process.

In some embodiments, it might be provided that the glass element hasbeen cut to length from a longer, especially continuous, glass tubestrand, such as by scratching and/or breaking.

It is cheap and easy to produce a glass tube strand and confectioningthis into smaller pieces in order to obtain a glass element ofappropriate length.

In some embodiments, it might be provided that the glass element hasbeen cleaned by at least one air stream applied at least in part to itsinner and/or outer surface such that at least some of the particleslocated on the respective surface(s) are blown away from the surfaceand/or out of the lumen, and/or the air stream is moved relative to theglass element from the middle section to the first or second end of theglass element.

A glass element is of particularly high quality if it has been cleanedappropriately.

In some embodiments, it might be provided that the glass element hasbeen shaken during the cleaning process, especially with a frequency of100 to 10000 Hz, such as 200 to 5000 Hz or 250 to 4000 Hz and/or anamplitude of 0.1 mm to 10 mm, such as 0.5 mm to 1 mm or 0.7 mm to 0.9mm.

Mechanical shaking of the glass element allows producing a glass elementwhich is particularly free of particles which otherwise might come offon their own from the surface such as the inner or outer surface of theglass element at some later time. Thus, safety is improved.

In some embodiments, it might be provided that the glass element iscleaned before it is reheated and/or after it has been cut from alonger, especially continuous, glass tube strand, such as by scratchingand/or breaking.

This allows ensuring that loose particles are removed so that they arenot heated and subsequently attach permanently at the surface. Hence,quality of the glass element is improved.

A glass element, such as the previously described glass element or anyembodiments described herein, which has been cleaned by and/or isobtainable by a method provided according to the invention or anyembodiment described herein, by a nozzle head provided according to theinvention or any embodiment described herein and/or by a cleaning systemprovided according to the invention or any embodiment described hereinis also provided.

In some exemplary embodiments provided according to the invention, abundle of glass elements, comprising a plurality, such as between 2 and500 or 50 to 200, of glass elements provided according to the inventionor any embodiment described herein is provided.

Having a bundle of high quality glass elements allows ensuring qualityover a large number of different glass elements which otherwise is notpossible.

Herein, a bundle may be a trading, loading or packaging unit fordistribution of glass elements, such as empty pharmaceutical cylindricalcontainers, i.e. pharmaceutical cylindrical containers filled with agas, e.g. air. For example, products usually, but not necessarily, ofthe same kind are combined as bundles when ordered together in retail orbundled in logistics. According to the invention, glass elements in thebundle can be separated by a spacer, for example a plastic or papersheet, so that they are not in direct contact with each other duringtransport. Usually, but not necessarily, the bundle is at least partlycovered by a plastic foil. In some embodiments, one bundle contains 5 to5000, such as 10 to 1000, 25 to 500, 50 to 300, or 75 to 250 glasselements. An example of a bundle is the DENSOPACK® from SCHOTT AG. Dueto economic reasons, the bundle may contain 25 to 500, such as 50 to 300or 75 to 250 glass elements, which are at least partly covered by aplastic foil and wherein the glass elements are in direct contact toeach other within the bundle. In some embodiments, the length of thehollow portion, such as the hollow cylindrical portion of the glasselements in the bundle is 2 cm or more, such as 10 cm or more, 20 cm ormore, 30 cm or more, 40 cm or more, 50 cm or more, or 100 cm or more,and/or 500 cm or less, such as 400 cm or less, 300 cm or less, 200 cm orless, 100 cm or less, or 50 cm or less.

In some embodiments, it might be provided that the bundle is at least inpart packed in a foil. A foil prevents the glass elements from furthercontaminations.

In some embodiments, it might be provided that at least some, such asall, of the plurality of glass elements are kept within the bundle at adistance from each other by at least one, such as a plurality of,spacing element(s).

A spacing element prevents the glass elements from damage. This makes itpossible to handle the bundle in a safe manner.

In some embodiments, it might be provided that at least some, such asall, of the plurality of glass elements are in direct contact with eachother.

A direct contact allows to reduce vibrations of the glass elements sothat the bundle can be handled more secure.

Referring now to the drawings, FIG. 1 shows a cross-sectional view of anozzle head 1 provided according to the invention in a firstconfiguration.

The nozzle head 1 is suitable for cleaning the inside of a glass elementwith a fluid 3. The fluid 3 is indicated by arrows.

The nozzle head 1 comprises a plurality of cleaning openings 5 (two ofwhich are shown in FIG. 1) for releasing at least one part of the fluid.Each of the cleaning openings 5 point in a first direction R1. Sinceeach of the plurality of cleaning openings 5 point in an individualfirst direction, thus, there are just as many first directions ascleaning openings.

The nozzle head 1 comprises one pressure balancing opening 7 forreleasing at least one part of the fluid 3 and pointing in a seconddirection R2. The pressure balancing opening 7 is arrangedconcentrically with regard to the center axis A of the nozzle head 1.

Two half spaces, a first one H1 and a second one H2, are separated by aplane P which is perpendicular to the center axis A.

Each of the first direction vectors of the first directions R1 point ina direction away from the second half space H2. The second directionvector of the second direction R2 points in a direction away from thefirst half space H1.

The nozzle head further comprises a feeding opening 9 for feeding thenozzle head 1 with the fluid 3. The feeding opening 9 is arrangedconcentrically with regard to the center axis A of the nozzle head 1.The feeding opening 9 points in a third direction R3. The thirddirection vector of the third direction R3 points in a direction awayfrom the second half space H2 and the third direction vector isanti-parallel to the second direction R2.

To be more precise, the nozzle head 1 comprises one single feedingopening 9 and one single pressure balancing opening 7 and the only onefeeding opening 9 is arranged opposite to the only one pressurebalancing opening 7 along the center axis A.

The nozzle head 1 comprises a supply channel 11 for supplying the fluid3 from the feeding opening 9 to the pressure balancing opening 7 and thecleaning openings 5. All pressure balancing and cleaning openings are influidal communication with each other via the supply channel 11.

The nozzle head 1 further comprises an adjustment element 13 foradjusting a third ratio of the fluid volume provided to all of thecleaning openings 5 and to the pressure balancing opening 7.

The adjustment element 13 comprises a dosage ring. The adjustmentelement 13 is arranged at least in part within the nozzle head 1. Theadjustment element 13 is moveable within the nozzle head 1 along anadjustment direction parallel to the center axis A. Thus, the thirdratio is or can be adjusted by moving the adjustment element 13 alongthe adjustment direction.

The nozzle head 1 further comprises a fixing element 15 for fixing theadjustment element 13 at a particular position, especially forpreventing a movement along the adjustment direction. The fixing element15 might be a locking nut.

The nozzle head 1 comprises a first threaded portion 17. The firstthreaded portion 17 is at least in part comprised by the feeding opening9. The adjustment element 13 comprises a second threaded portion 19,which cooperates with the first threaded portion 17 of the feedingopening 9. The cooperation allows to move the adjustment element 15along the adjustment direction. Of course, the fixing element 15 has tobe released during moving.

FIG. 2 shows a cross-sectional view of the nozzle head 1 in a secondconfiguration.

In that second configuration, the third ratio has been adjusted bymoving the adjustment element 13 along the adjustment direction, i.e tothe left in FIGS. 1 and 2. As indicated in that there is only one arrowpresent in each of the cleaning openings 5 in FIG. 2 (compared to two inFIG. 1), less fluid 3 fed into the feeding opening 9 is released by thecleaning openings in the second configuration compared to the firstconfiguration. The adjustment of the third ratio is accomplished in thatbasically the adjustment element 13 decreases a cross-section of each ofthe cleaning openings.

FIG. 3 shows a cross-sectional view of an exemplary embodiment of acleaning system 100 provided according to the invention.

The cleaning system 100 comprises a nozzle head 101. The nozzle head 101might be the nozzle head 1 described above with respect to FIGS. 1 and2. Hence, for the same structural features of the nozzle head 101 thesame reference numerals are used as for the nozzle head 1, however,increased by 100. Furthermore, for all aspects concerning the nozzlehead 101, reference can be made to the description provided previouslywith respect to nozzle head 1 in combination with FIGS. 1 and 2.

The cleaning system 100 also comprises a fluid supply line 121, which isconnected to the feeding opening 109 of the nozzle head 101. Indeed, theadjustment element 113 is designed integrally with the fluid supply line121.

FIGS. 4A and 4B show a perspective view of another exemplary embodimentof a cleaning system 200 provided according to the invention,respectively, in an assembled and disassembled state.

Indeed, the cleaning system 200 is similar to the cleaning system 100described previously with respect to FIG. 3. Hence, for the samestructural features the same reference numerals are used, however,increased by 100.

In FIG. 4A the cleaning system 200 is shown in an assembled state. InFIG. 4B the cleaning system 200 is shown disassembled into parts. It isapparent from FIG. 4B that the adjustment element 113 and the fixingelement 215 can be separated from the remaining nozzle head 201. Theadjustment element is designed in one piece with the fluid supply line221.

FIG. 5 shows a perspective view of another exemplary embodiment of acleaning system 300 provided according to the invention.

Indeed, the cleaning system 300 is similar to the cleaning systems 100and 200 described previously, respectively, with respect to FIG. 3 andFIGS. 4A and 4B. Hence, for the same structural features the samereference numerals are used, however, increased by 200 or 100.Furthermore, only the differences between the cleaning system 300 andthe cleaning systems 100 and 200 need to be discussed here, while forthe remainder reference can be made to the description providedpreviously with respect to the cleaning systems 100 and 200 incombination with FIG. 3 and FIGS. 4A and 4B.

In cleaning system 300, the nozzle head 301 is designed integrally withthe fluid supply line 321. The nozzle head 301, therefore, does not needand does not have a fixing element. The nozzle head 301 has also noadjustment element. Consequently, there are also no first and secondthreaded portions required. Nozzle head 301, thus, cleaning system 300is, therefore, particularly robust and cheap.

A nozzle head, such as the nozzle head 301 of cleaning system 300, mightbe produced by a 3D printing technology. This allows realizing alsodesigns of nozzle heads which are hard to produce in a conventionalmanner.

FIG. 6 shows a perspective view of another exemplary embodiment of acleaning system 400 provided according to the invention.

Indeed, the cleaning system 400 is similar to the cleaning systems 100and 200 described previously, respectively, with respect to FIG. 3 andFIGS. 4A and 4B. Hence, for the same structural features the samereference numerals are used, however, increased by 300 or 200.Furthermore, only the differences between the cleaning system 400 andthe cleaning systems 100 and 200 need to be discussed here, while forthe remainder reference can be made to the description provided abovewith respect to the cleaning systems 100 and 200 in combination withFIG. 3 and FIGS. 4A and 4B.

In cleaning system 400, the nozzle head 401 does not have a fixingelement. This is also possible, for example, in situations where thereis enough friction between the two threaded portions (only the secondthreaded portion 419 is visible in FIG. 6) so that the adjustmentelement is not moved unintentionally within the nozzle head.

FIG. 7 shows an illustration with multiple subsequent time steps T1-T5demonstrating how a cleaning system 500 provided according to theinvention can be used for cleaning the inside of a glass element 501with a fluid 503.

For the purpose of illustration, the cleaning system 500 is shown onlywith its nozzle head 505 and supply line 507. The glass element 501might be a glass tube.

The cleaning system 500 is configured to clean the glass element fromparticles in that the nozzle head 505 is moved along a fourth directionR4 inside the glass element 501 while the nozzle head 505 does notrelease fluid (see time steps T1 and T2) and the nozzle head 505 ismoved in a fifth direction R5 out of the glass element 501 while thenozzle head 505 releases fluid (see time steps T3, T4 and T5). Thefourth direction R4 is parallel to the second direction of the nozzlehead. The fifth direction R5 is parallel to the third direction of thenozzle head.

Of course, any cleaning system provided according to the invention, suchas any one of the cleaning systems 200, 300 and 400 describedpreviously, might be configured accordingly.

FIG. 8 shows an alternative to the illustration of FIG. 7. Here, twocleaning systems 500 a, 500 b are used to clean the glass element 501from two ends simultaneously. Only the last three time steps are shown.Of course, in order to clean the glass element 501 also in the center ina precise manner, it might be possible to advance the movement of one ofthe two systems 500 a, 500 b so that the nozzle heads 503 a, 503 b donot collide at the center of the glass element 501.

While this invention has been described with respect to at least oneembodiment, the present invention can be further modified within thespirit and scope of this disclosure. This application is thereforeintended to cover any variations, uses, or adaptations of the inventionusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this invention pertains andwhich fall within the limits of the appended claims.

LIST OF REFERENCE NUMERALS

-   1, 101, 201, 301, 401 Nozzle head-   3, 103 Fluid-   5, 105, 205, 305, 405 Opening-   7, 107, 207, 307, 407 Opening-   9, 109, 209 Opening-   11, 111, 211 Supply channel-   13, 113, 213 Adjustment Element-   15, 115, 215 Fixing element-   17, 117, 217 Threaded Portion-   19, 119, 219, 419 Threaded Portion-   121, 221, 321, 421 Fluid Supply line-   100, 200, 300, 400, 500 Cleaning System-   501 Glass element-   503, 503 a, 503 b Fluid-   505, 505 a, 505 b Nozzle head-   507, 507 a, 507 b Fluid Supply line-   A Axis-   H1, H2 Half Space-   P Plane-   R1, R2, R3, R4, R5 Direction-   T1, T2, T3, T4, T5 Time step

What is claimed is:
 1. At least one glass element, comprising: a firstend; a second end; and a hollow portion comprising a first end sectioncomprising the first end of the at least one glass element, a middlesection, and a second end section comprising the second end of the atleast one glass element, each section having an inner surface and anouter surface and all sections are of equal length, wherein a ratio of anumber of particles on the inner surface at the first end section and/orthe second end section to a number of particles on the inner surface atthe middle section is 20 or less.
 2. The at least one glass element ofclaim 1, wherein the ratio of the number of particles on the innersurface at the first end section and/or the second end section to thenumber of particles on the inner surface at the middle section is 15 orless.
 3. The at least one glass element of claim 2, wherein the ratio ofthe number of particles on the inner surface at the first end sectionand/or the second end section to the number of particles on the innersurface at the middle section is 4 or less.
 4. The at least one glasselement of claim 2, wherein the ratio of the number of particles on theinner surface at the first end section and/or the second end section tothe number of particles on the inner surface at the middle section is1.0 or more.
 5. The at least one glass element of claim 1, wherein theratio of the number of particles on the inner surface at the first endsection and/or the second end section to the number of particles on theinner surface at the middle section is 1.0 or more.
 6. The at least oneglass element of claim 1, wherein the number of particles on the innersurface at the first end section and/or the second end section is 0 ormore.
 7. The at least one glass element of claim 6, wherein the numberof particles on the inner surface at the first end section and/or thesecond end section is 50 or more.
 8. The at least one glass element ofclaim 6, wherein the number of particles on the inner surface at thefirst end section and/or the second end section is 1000 or less.
 9. Theat least one glass element of claim 1, wherein the number of particleson the inner surface at the first end section and/or the second endsection is 1000 or less.
 10. The at least one glass element of claim 1,wherein each particle of the number of particles has a particle size of50 μm or more.
 11. The at least one glass element of claim 10, whereineach particle of the number of particles has a particle size of 1000 μmor less.
 12. The at least one glass element of claim 10, wherein theparticle size of each particle is a longest extension of the particle.13. The at least one glass element of claim 1, wherein each particle ofthe number of particles has a particle size of 1000 μm or less.
 14. Theat least one glass element of claim 1, wherein the at least one glasselement does not contain any particles on the inner surface at the firstend section and/or the second end section having a particle size of 1000μm or more.
 15. The at least one glass element of claim 1, wherein theparticles are inorganic particles and/or are selected from the groupconsisting of glass, metal, dust, salt, and mixtures thereof.
 16. The atleast one glass element of claim 1, wherein the at least one glasselement comprises a plurality of glass elements to form a bundle ofglass elements.
 17. The at least one glass element of claim 16, whereinthe plurality of glass elements comprises between 2 and 500 glasselements.
 18. A cleaning system for cleaning the inside of a glasselement with a fluid, the cleaning system comprising: a nozzle headcomprising: a cleaning opening for releasing a part of the fluid andpointing in a first direction; and a pressure balancing opening forreleasing a part of the fluid and pointing in a second direction,wherein two half spaces comprising a first one and a second one areseparated by a plane which is perpendicular to a center axis of thenozzle head, wherein a first direction vector of the first directionpoints in a direction at least one of towards the first half space oraway from the second half space, wherein a second direction vector ofthe second direction points in a direction at least one of towards thesecond half space or away from the first half space.
 19. The cleaningsystem of claim 18, wherein the nozzle head comprises a feeding opening,the cleaning system further comprising a fluid supply line that isconnected to the feeding opening of the nozzle head.